The immune system is a highly complex orchestration of several sub-systems which protect the host against infectious agents and cancerous cells. The immune system performs surveillance and must appropriately attack pathogens; it must also be able to recognize and spare cells which belong to the host. Immunomodulation is the ability of the hormones and other molecules to selectively alter the sensitivity of the immune system to mount attacks in response to antigenic stimulation. This is preferred to overstimulation (or hypersensitivity) of the immune system which may lead to damage to the host cells. The immune system consists of two major parts, namely the innate arm and the adaptive arm.
Said adaptive arm rests on the intricate interplay of various types of immune cells like dendritic cells, T-cells and B-cells as well as a wide range of immunomodulatory substances like cytokines to mount a successful production of antibodies. However, if the immune system encounters a foreign antigen for the first time, its reaction is frequently too slow/too weak to stop the initial spread of said antigen. Thus, there is a need to keep the immune system in a “primed” or heightened state of alert prior to the first encounter of a foreign antigen.
Furthermore, there is a need to enhance an on-going immune response in order to have the immune system clear the foreign antigen from the body as quickly as possible.
In order to help the immune system ward off potentially harmful invaders, a method of artificial induction of an immune response called “vaccination” was systematically employed for the first time in the 18th century. Vaccination is the administration of antigenic material (the vaccine) to produce immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by a pathogen. Vaccination is generally considered to be the most effective and cost-effective method of preventing infectious diseases. The material administered can either be live but weakened forms of pathogens (bacteria or viruses), killed or inactivated forms of these pathogens, or purified material such as proteins.
However, a vaccination with the antigenic material alone frequently fails to provoke an immune response that is sufficiently strong to convey complete or even partial immunity. Thus, adjuvants are used to boost the immune response. Broadly speaking, adjuvants fall into two classes: inorganic and organic adjuvants.
Typical examples of inorganic adjuvants are aluminium salts, e.g. aluminium phosphate and aluminium hydroxide. Due to their low to non-existent toxicity, they are the most widely used adjuvants in human vaccinations.
Organic adjuvants are usually selected from components of the bacterial cell wall like lipopolysaccharide (LPS) and from endocytosed nucleic acids such as double-stranded RNA (dsRNA), single-stranded DNA (ssDNA), and unmethylated CpG dinucleotide-containing DNA. The reason for this is that immune systems have evolved to recognize and react against these specific antigenic moieties.
Thus, there is a need for additional adjuvants that help boost an immune response while at the same time being non-toxic and that do not induce any severe side effects in subjects.
Larch Arabinogalactan is a highly branched polysaccharide that is composed of galactose units and arabinose units in the approximate ratio of 6:1. It is a fine, dry, light brown powder with neutral taste and, in case it is extracted from larch trees, a mild pine-like odour. It dissolves quickly in water or juice.
Studies on improvement of response to a pneumococcal vaccine by adults include revaccination, the addition on conjugates to the vaccine and alternative antigenic substances.[1] Experiments have also been conducted on the use of supplements, including zinc, vitamin A and L-arginine to increase the response to the vaccine.[2,3] Some plants are known to contain substances that modulate the immune system. As an example, an extract of the plant Uncana tomentosa was reported to enhance the response to a pneumococcal vaccine in male volunteers, elevating lymphocyte/neutrophil ratios and increasing the persistence of the antibody response to the vaccine.[4]
Several immune-enhancing herbs, including Echinacea purpurea, Baptista tinctoria, Thuja occidentalis, Angelica acutiloba, and Curucuma longa and the medicinal mushroom Ganoderma lucidum contain compounds known as Arabinogalactans.[5] Larch arabinogalactan has demonstrated immunomodulating activity in vitro and in vivo.[6,7]. However, said immunomodulating effect was thus far limited to the innate arm of the immune system. Nothing in the state of the art indicates that Larch Arabinogalactan is capable of modulating the adaptive arm of the immune system.